Hello, i am new to this site but am in desperate need of help. I have a 1998 s10 with a 4.3L auto, 2wd and the truck is all prerunnered out, including a fuel cell and think that might be the problem. right now the truck runs terrible, it shakes, stalls and at start up and first 1/4 mile of driving puffs out black smoke. The codes that it reads are P0101, P0300 and P0452. Now i went to autozone and figured out what they are and came up with teh random misfire, mass or volume air flow circuit and evap control system pressure sensor low input.
What i think is the main issue is that the truck has a fuel cell and an aftermarket fuel pump,and i am not able to locate a fuel pressure sensor or regulator. and this is causing a lean misfire which is causing the computer to try and richen the fuel even though it is probably already recieving too much fuel.
All of the codes indicate that a possible problem could be the fuel pressure, and so i was wondering if that seems the logical choice and also how do i check the pressure and what should it be at. also if it is getting too much fuel, am i able to put on a OE pressure regulator with the aftermarket pump, also where would the pressure regulator and the fuel pressure sensor be located???
Any other input on how to resolve my issue and get the truck running so it would pass emissions test would be greatly appreciated and thanks in advanced.

 

Have you tested for good and consistant fuel pressure? There is a relatively inexspensive guage that you can get from Autozone to check with. Looks like a tire guage and hooks to s schrader valve either right inside the firewall or up by the throttle body. Weak is 50-52 or less. Is there still an inline fuel filter? Changed when?